This patch fixes crash after resuming from hibernation. The issue
occurs when mhi stack is builtin and so part of the 'restore-kernel',
causing the device to be resumed from 'restored kernel' with a no
more valid context (memory mappings etc...) and leading to spurious
crashes.
This patch fixes the issue by implementing proper freeze/restore
callbacks.
Reported-by: Shujun Wang <wsj20369@xxxxxxx>
Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
---
drivers/bus/mhi/pci_generic.c | 36 +++++++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)
diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c
index aa8f8d5..afa8763 100644
--- a/drivers/bus/mhi/pci_generic.c
+++ b/drivers/bus/mhi/pci_generic.c
@@ -888,9 +888,43 @@ static int __maybe_unused mhi_pci_resume(struct device *dev)
return ret;
}
+static int __maybe_unused mhi_pci_freeze(struct device *dev)
+{
+ struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev);
+ struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
+
+ /* We want to stop all operations, hibernation does not guarantee that
+ * device will be in the same state as before freezing, especially if
+ * the intermediate restore kernel reinitializes MHI device with new
+ * context.
+ */
+ if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
+ mhi_power_down(mhi_cntrl, false);
+ mhi_unprepare_after_power_down(mhi_cntrl);
+ }
+
+ return 0;
+}
+
+static int __maybe_unused mhi_pci_restore(struct device *dev)
+{
+ struct mhi_pci_device *mhi_pdev = dev_get_drvdata(dev);
+
+ /* Reinitialize the device */
+ queue_work(system_long_wq, &mhi_pdev->recovery_work);
+
+ return 0;
+}
+
static const struct dev_pm_ops mhi_pci_pm_ops = {
SET_RUNTIME_PM_OPS(mhi_pci_runtime_suspend, mhi_pci_runtime_resume, NULL)
- SET_SYSTEM_SLEEP_PM_OPS(mhi_pci_suspend, mhi_pci_resume)
+#ifdef CONFIG_PM_SLEEP
+ .suspend = mhi_pci_suspend,
+ .resume = mhi_pci_resume,
+ .freeze = mhi_pci_freeze,
+ .thaw = mhi_pci_restore,
+ .restore = mhi_pci_restore,
+#endif
};
static struct pci_driver mhi_pci_driver = {
--
2.7.4
